Field of the Disclosure
Embodiments of the present disclosure relate to a twin laundry machine, more particularly, to a twin laundry machine configured to control mutual motor operations of one or more laundry machines provided therein not to be overlapped with each other, in case the one or more laundry machines are put into operation to perform washing.
Embodiments of the present disclosure also relate to a twin laundry machine of which a motor for driving a drum has an improved heat radiation function, more particularly, to a twin laundry machine which includes a sub-washing machine with a smaller size than a normal washing machine and frequent exposure to high temperature usage environments.
Embodiments of the present disclosure also relate to a drive unit of a laundry machine which is capable of improving the function of heat-radiation performed by a drive for driving a drum, and a laundry machine having the same.
Discussion of the Related Art
A conventional laundry machine is used in treating laundry or washing objects through diverse operations combined with washing, spinning and/or drying cycles.
Such a conventional laundry machine includes a washing machine configured to wash laundry such as clothes and beddings by using the emulsification activity of detergent, the water current activity generated by the rotation of a tub or pulsator and the mechanical power applied by the pulsator; a dryer configured to dry laundry by applying hot air or cold air to the laundry; and a refresher configured to remove wrinkles from clothes by applying steam. Also, there are diverse types of laundry machines configured to provide diverse functions such as a washing machine having a washing function and a drying function.
The conventional laundry machine has to be provided with the minimum amount of wash water needed to perform washing. If a large volume of a tub is provided, unnecessarily much wash water has to be provided even in washing a small amount of laundry.
To solve such a disadvantage of water waste, a mini-washing machine or a washing machine for infants has been provided.
However, it causes a spatial disadvantage to install both one conventional laundry machine and one mini-washing machine together so as to use both of them. It also causes a design disadvantage to use the conventional laundry machine and the mini-washing machine which have different designs and versions.
Recently, a twin laundry machine including two washing machines is provided to address the problem. The twin laundry machine is provided as one body with two units (or two washing machines). Specifically, a first washing unit and a second washing unit are installed as if having one body so as to make better use of a space and improve use convenience and provide an effectively beautiful design.
The first washing unit provided in the twin laundry machine may be a main-washing machine with a relatively large size and the second washing unit may be a sub-washing machine or a mini-washing machine with a relatively small size. The volume of the first washing machine for washing or drying is larger than that of the second washing unit. Accordingly, a user seems to be able to use one of the two washing machines selectively according to needs and give specific functions to each of the washing machines. The user can be provided with the specialized functions that cannot be provided when having one laundry machine.
Vibration might be caused when the two washing units perform washing at the same time or two twin laundry machines are put into operation. In this instance, the vibration results in errors of the twin laundry machine and power consumption might drastically rise. The washing units are not completely and physically separated from each other and the vibration generated in one of the washing units could directly affect the other washing unit.
As one usage example of the twin laundry machine, the second washing unit is provided in main consideration of sanitation and it is used in treating infant clothes or underwear. Accordingly, the second washing unit is used a lot in sterilizing laundry in boiling water which is heated to a preset high temperature. A sterilize-washing course takes a relatively long time to simply heat wash water to a preset high temperature and keep the high temperature after that. In other words, the sterilize-washing course is implemented to perform washing in a state where wash water is kept at a high temperature for a relatively long time.
To perform the sterilize-washing course, a heater is driven to heat wash water to a preset high temperature. Different from the first washing unit with the normal size, the second washing unit has a relatively small size and volume with a tiny internal space. Accordingly, the heat generated while the wash water is heated to the preset high temperature seems to be transferred to the other components which are provided nearby.
Especially, the high-temperature heat happens to affect the drive unit configured to drive the second washing unit. For example, the high-temperature heat might be transferred to a motor for driving a drum provided in the second washing unit.
The motor generates heat by its own driving. If exposed to a preset high temperature or more, the motor fails to drive normally and happens to damage or stop its drive unexpectedly. Especially, it is quite important to keep a stator which generates much heat out of overheat.
FIG. 1 illustrates a schematic diagram of a rotor provided in a motor of the conventional laundry and FIG. 2 is a sectional diagram illustrating an air inlet part shown in FIG. 1 along a circumferential direction.
A stator of the motor may be coupled to an outer rear wall of a tub, and a drum may be rotatably mounted in a tub.
As shown in FIG. 1, the rotor 10 includes a rotor frame 20 and a plurality of magnets 60. The rotor frame 20 includes a side wall 30 to which the plurality of the magnets 60 are mounted; and a bottom wall 40.
A central portion of the bottom wall 40 is connected to a shaft of the drum. When the rotor is rotated by the electromagnetic force generated between the stator and the rotor, the rotational force of the rotor is transferred to the drum shaft and the drum.
On a FIG. 1 basis, the side wall 30 is vertically extended upward from the bottom wall 40. In other words, the side wall 30 is extended from a radial-direction end of the circular bottom wall.
The shape of the side wall 30 and the bottom wall 40 allows the rotor frame 20 to have a container-shaped appearance so as to define an internal space. The stator is disposed in the internal space of the rotor frame 20.
It is well known that the stator is coupled to the tub through the central portion of the tub and a coil is provided distant from a center of the stator in a radial direction. Corresponding to the stator, an air inlet part 41 is provided. In other words, the air inlet part 41 is provided in the bottom wall 40 and a plurality of air inlet parts 41 may be provided along a circumferential direction. A plurality of openings 43 may be defined.
A hub 50 is formed in the central portion of the bottom wall 40 and a connector may be coupled to the hub 50. The connector may be connected to the drum shaft.
An embossing portion 44 may be formed in the bottom wall 40. In this instance, a plurality of embossing portions 44 may be provided along a circumferential direction. The embossing portions 44 and the air inlet parts 41 may be arranged alternatively.
The embossing portions 44 may be provided to reinforce the stiffness of the rotor frame 20, especially, the bottom wall 40. The bottom wall 40 is formed as a thin plate so that distortion or floppiness might be generated in the bottom wall 40 during the rotation of the rotor 10. To minimize such distortion or floppiness, the embossing portions 44 may be provided.
The air inlet parts 41 may be provided to suck external air, in other words, cold air into the rotor. On a FIG. 2 basis, the air inlet parts 41 may be provided to suck air upward from a lower portion of the rotor.
When the rotor 10 is rotated, air flux may be generated in the internal space of the rotor (in other words, the space where the stator is provided) by a blade 42 and the pressure inside the rotor is relatively lower than the pressure outside the rotor. In addition, the air heated by the stator tends to go up.
Accordingly, when the rotor 10 is rotated, external cold air is sucked into the stator via the air inlet parts 41 and hot air inside the stator goes up and outside via a gap between the stator and the rotor or the space between the stator and the tub.
The rotor having the structure of the air inlet parts 41 has no big problem chilling the stator.
Different from the conventional motor, the motor for driving the second washing unit could be exposed not only to the heat generated therein, especially, the stator but also the heat transferred from the hot tub arranged nearby. Accordingly, such the heat has to be radiated effectively enough to keep the driving of the drum.
However, the rotor having the structure of the conventional air inlet parts 41 only chills the heat generated in the stator but fails to provide a satisfactory cooling function if the heat transferred from the hot tub is added.
That is because the holes for sucking external air into the rotor are aligned or parallel with the rotational direction of the rotor. In other words, external air cannot be sucked into the rotor smoothly.
Moreover, the blade is extended near the holes toward the stator and disposed in the rotor so that it directly blows internal air of the rotor, not external air. As the blade blows relatively-high-temperature air toward the stator, not external air, the cooling efficiency may become lower.
It may be considered to enhance the cooling efficiency that the blade 42 is formed higher. However, such the blade stands high toward the stator and it is limited to increase the height of the blade. If the blade becomes higher, the rotor also has to become higher. Accordingly, it is also limited because of the small installation space and the relatively small size.
It is necessary to invent and provide a motor which is capable of effectively and efficiently radiating not only the heat generated in the stator but also the heat transferred from a surrounding high-temperature environment and a drive unit including such a motor which is provided in a laundry machine.
It is also necessary to invent and provide a second washing unit which has an improved reliability by effective radiating of the heat generated in a drive unit of the second washing unit and a twin laundry machine having such a second washing unit.
Moreover, it is necessary to invent and provide a twin laundry machine which has the improved reliability and durability of first and second washing units by minimizing of the influence of the heat generated in a drive unit of the second washing unit on the first washing unit.